Polymer treatment in the flowing afterglow of an oxygen microwave discharge: Active species profile concentrations and kinetics of the functionalization

1995 ◽  
Vol 15 (2) ◽  
pp. 173-198 ◽  
Author(s):  
F. Normand ◽  
A. Granier ◽  
P. Leprince ◽  
J. Marec ◽  
M. K. Shi ◽  
...  
Keyword(s):  
Microwave Discharge ◽  
Active Species ◽  
Flowing Afterglow ◽  
Kinetics Of

Reactions of Polymer Films with Active Species Produced in a Microwave Discharge*

1975 ◽  
Vol 10 (1) ◽  
pp. 72-76 ◽  
Author(s):  
J. T. Books ◽  
J. P. Wightman
Keyword(s):  
Polymer Films ◽  
Microwave Discharge ◽  
Active Species

A Model for the Kinetics of Oxygen Dissociation in a Microwave Discharge

1973 ◽  
Vol 12 (1) ◽  
pp. 90-94 ◽  
Author(s):  
Alexis T. Bell ◽  
Kam Kwong
Keyword(s):  
Microwave Discharge ◽  
Oxygen Dissociation ◽  
Kinetics Of

Studies on Hydrogen–Oxygen Systems in the Electrical Discharge. VII. Deuterium Isotope Effects in the Chemistry of the Hydrogen Polyoxides

1975 ◽  
Vol 53 (16) ◽  
pp. 2490-2497 ◽  
Author(s):  
José L. Arnau ◽  
Paul A. Giguère
Keyword(s):  
Hydrogen Peroxide ◽  
Electrical Discharge ◽  
Microwave Discharge ◽  
Isotope Effects ◽  
Cold Trap ◽  
Manometric Method ◽  
Deuterium Isotope Effects ◽  
Kinetics Of ◽  
Hydrogen Polyoxides ◽  
Hydrogen Peroxide Vapor

The kinetics of oxygen evolution on warming the trapped products (at −196 °C) from water or hydrogen peroxide vapor dissociated in a glow discharge were studied by the manometric method. Under closely controlled conditions it was possible to distinguish clearly the decomposition of the two intermediates, H2O3 and H2O4. The latter begins to decompose measurably following crystallization of the glassy solid at about −115°; the trioxide decomposes readily between −50 and −35°. Typically, the yields of H2O3 from dissociated water vapor were of the order of 3 to 5 mol%; those of H2O4, only about one-tenth as much. Varying the distance between the microwave discharge and the cold trap was found to affect differently the yields of the various products. Those of water and peroxide showed a simple, direct correlation; the minor constituents H2O3 and H2O4 followed entirely different patterns. Only a small fraction of the peroxide is formed via the H2O4 intermediate in these systems. Less water, and more of the higher oxides, were obtained from dissociated hydrogen peroxide than from water vapor.The deuterated systems showed some unusual isotope effects. The yields of D2O3 were always higher (up to twice and even more) than those of H2O3 under similar conditions. The other products showed little or no such effect, except for occluded oxygen and ozone which decreased by about half. Finally, the deuterium polyoxides decompose at slightly higher temperatures (10 to 15°) than their hydrogen analogs. Mechanisms are proposed for the formation and decomposition of the polyoxides.

Ammonium tetrathiomolybdate as a novel electrode material for convenient tuning of the kinetics of electrochemical O2 reduction by using iron–porphyrin catalysts

2016 ◽  
Vol 4 (18) ◽  
pp. 6819-6823 ◽  
Author(s):  
Sudipta Chatterjee ◽  
Kushal Sengupta ◽  
Sabyasachi Bandyopadhyay ◽  
Abhishek Dey
Keyword(s):  
Electron Transfer ◽  
Electrode Material ◽  
Deposition Time ◽  
Active Species ◽  
Iron Porphyrin ◽  
Gold Electrodes ◽  
Redox Active ◽  
O2 Reduction ◽  
Ammonium Tetrathiomolybdate ◽  
Kinetics Of

Ammonium tetrathiomolybdate modified gold electrodes can easily tune the rate of electron transfer to the redox active species when the deposition time is varied.

Mobilization of copper(II) from plasma components and mechanisms of hepatic copper transport

1984 ◽  
Vol 246 (1) ◽  
pp. G72-G79 ◽  
Author(s):  
H. M. Darwish ◽  
J. C. Cheney ◽  
R. C. Schmitt ◽  
M. J. Ettinger
Keyword(s):  
Active Species ◽  
Copper Transport ◽  
Inhibitory Effects ◽  
Facilitation Effect ◽  
Molar Ratios ◽  
Hepatic Copper ◽  
Plasma Fraction ◽  
Ionic Copper ◽  
Parenchymal Cells ◽  
Kinetics Of

The effects of plasma Cu(II) ligands on the kinetics of Cu(II) transport by rat liver parenchymal cells were determined to examine how Cu(II) is mobilized from plasma and transported into liver cells. Albumin markedly inhibited Cu(II) uptake at Cu(II)-to-albumin molar ratios of 3:1 or less. Kinetic analyses showed that albumin inhibits Cu(II) uptake by reducing the concentration of free Cu(II) in solution. Under conditions of excess albumin to Cu(II), histidine facilitated albumin-inhibited uptake of Cu(II). Threonine, glutamine, and most other amino acids were without effect. Moreover, the facilitation effect of a low-molecular-weight plasma fraction (less than or equal to 5,000) was largely accounted for by its histidine concentration. The tripeptide Gly-His-Lys also inhibited Cu(II) uptake into hepatocytes by the same mechanism as albumin. The inhibitory effects of albumin and Gly-His-Lys were additive with or without histidine. The active species in the Cu(II), albumin, and histamine mixtures was shown to be the His2Cu(II) complex. Vmax for this complex was identical to the Vmax for free Cu(II), but the Km was slightly higher [15 microM vs. 11 microM for free Cu(II)]. Concurrent determinations of [3H]-histidine and 64Cu(II) uptake showed that histidine was not transported with Cu(II) from His X Cu(II) or His2Cu(II) complexes. The data are consistent with histidine mobilizing Cu(II) from albumin by competing for Cu(II), interaction of the His2Cu(II) complex with the putative hepatic copper transport protein, and transport of copper as free ionic copper.

Esterification and its Kinetics of Acetic Acid with 2-Methoxyethanol over a Ce-Pillared Layer Clay Catalyst

2011 ◽  
Vol 415-417 ◽  
pp. 126-132
Author(s):  
Yong Jie Wang
Keyword(s):  
Acetic Acid ◽  
Liquid Phase ◽  
Ion Exchange ◽  
External Surface ◽  
Active Species ◽  
Clay Catalyst ◽  
Kinetics Of

A novel clay containing a heterogenized Ce(SO4)2 complex (Ce-bentonite) has been prepared via ion exchange of a Chinese Na+-bentonite with pillared layer clay complex. It was established that the active species [Ce(OH)3]+ was situated on the external surface of the catalyst, which was found to be efficient in the liquid-phase esterification of acetic acid with 2-methoxyethanol.

The electric oxygen-iodine laser: chemical kinetics of O 2 (a1Δ) production and I(2P 1/2 ) excitation in microwave discharge systems

2006 ◽  
Author(s):  
W. T. Rawlins ◽  
S. Lee ◽  
W. J. Kessler ◽  
D. B. Oakes ◽  
L. G. Piper ◽  
...  
Keyword(s):  
Chemical Kinetics ◽  
Microwave Discharge ◽  
Iodine Laser ◽  
Kinetics Of

scholarly journals How to Control the Rate of Heterogeneous Electron Transfer Across the Rim of M6L12 and M12L24 Nanospheres

2020 ◽  
Author(s):  
Riccardo Zaffaroni ◽  
Eduard.O. Bobylev ◽  
Plessius, Raoul ◽  
Jarl Ivar van der Vlugt ◽  
Joost reek
Keyword(s):  
Electron Transfer ◽  
Active Species ◽  
Transition Metal Catalysts ◽  
Supramolecular Assemblies ◽  
Fine Tuning ◽  
Transfer Rates ◽  
Heterogeneous Electron Transfer ◽  
Redox Active ◽  
Kinetics Of ◽  
Fine Tune

Catalysis in confined spaces, such as provided by supramolecular cages, is quickly gaining momentum. It allows for second coordination sphere strategies to control the selectivity and activity of transition metal catalysts, beyond the classical methods like fine-tuning the steric and electronic properties of the coordinating ligands. Only a few electrocatalytic reactions within cages have been reported, and there is no information regarding the electron transfer kinetics and thermodynamics of redox-active species encapsulated into supramolecular assemblies. This contribution revolves around the preparation of M<sub>6</sub>L<sub>12 </sub>and larger M<sub>12</sub>L<sub>24</sub> (M= Pd or Pt) nanospheres functionalized with different numbers of redox-active probes encapsulated within their cavity, either in a covalent fashion via different types of linkers (flexible, rigid and conjugated or rigid and non-conjugated) or by supramolecular hydrogen bonding interactions. The redox-probes can be addressed by electrochemical electron transfer across the rim of nanospheres and the thermodynamics and kinetics of this process are described. Our study identifies that the linker type and the number of redox probes within the cage are useful handles to fine-tune the electron transfer rates, paving the way for the encapsulation of electro-active catalysts and electrocatalytic applications of such supramolecular assemblies.

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